Read the source given below and answer the questions that follow: The present composition of earth’s atmosphere is chiefly contributed by nitrogen and oxygen. There are three stages in the evolution of the present atmosphere. The first stage is marked by the loss of primordial atmosphere. In the second stage, the hot interior of the earth contributed to the evolution of the atmosphere. Finally, the composition of the atmosphere was modified by the living world through the process of photosynthesis. The early atmosphere, with hydrogen and helium, is supposed to have been stripped off as a result of the solar winds. This happened not only in case of the earth, but also in all the terrestrial planets, which were supposed to have lost their primordial atmosphere through the impact of solar winds. During the cooling of the earth, gases and water vapour were released from the interior of the solid earth. This started the evolution of the present atmosphere. Continuous volcanic eruption contributed water vapour and gases to the atmosphere. As the earth cooled, the water vapour released started getting condensed. The carbon dioxide in the atmosphere got dissolved in rain water and the temperature further decreased causing more condensation and more rains. The rainwater falling onto the surface got collected in the depression to give rise to oceans. The earth’s oceans were formed within 500 million years from the formation of the earth.
i. How was finally the atmosphere formed?
a. By the loss of primordial atmosphere
b. By the hot interior of the earth
c. By the process of photosynthesis
d. By the release of watervapour
ii. Why is the earth not covered with hydrogen and helium gases as Jupiter
and Saturn?
a. Due to the process of photosynthesis
b. Due to condensation
c. Due to the impact of the solar winds
d. Noe of the above
iii. How was the oceans filled with water?
a. Due to the volcanic eruption
b. Due to the solar winds
c. Due to the cooling down of the earth
d. All of the above.
Answers
Answer:
1)option B
When Earth formed 4.6 billion years ago from a hot mix of gases and solids, it had almost no atmosphere. The surface was molten. As Earth cooled, an atmosphere formed mainly from gases spewed from volcanoes. It included hydrogen sulfide, methane, and ten to 200 times as much carbon dioxide as today's atmosphere.
2(none of the above
A large planet such as Jupiter has enough gravity to hold on to most of its hydrogen and helium, which is why these elements dominate the atmospheres of gas giants. But the gravity of Earth isn't strong enough, so Earth's early atmosphere of helium and free hydrogen evaporated into space.
3) option C
The ocean formed billions of years ago.
At this time, about 3.8 billion years ago, the water condensed into rain which filled the basins that we now know as our world ocean. ... As the water drained into the great hollows in the Earth's surface, the primeval ocean came into existence
Explanation:
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